It's the only very paranoid explanation I can come up with as to how someone who is massively digitally inept can know the information they know about me. They've no-one else to ask and the information isn't freely out there. We're not in touch and we have no common friends.
I've no idea how easy it is to find a PI to work for you, or for them to find out information about you, including contact details.
I'm terribly boring really, they wouldn't have had much fun following me, if that is how it's been done! Just wondering what the chances are of the information having been found out this way? Someone on MN must be one!
You wouldn't know if they're any good at their job, I guess.